1. Field of the Invention
The present invention relates to a method of controlling a multi-tasking excavator system, more particulary, to a method which is scheduled to enable urgent jobs to be quickly executed and in which a response speed of the system to the jobs is improved to achieve proper response required to perform the jobs.
2. Description of the Prior Art
In a conventional excavator control system, an electronic control device is employed to perform desired jobs in order.
With such an excavator control device, it is difficult to effectively process the jobs. Therefore, urgent jobs must be quickly effected or than a job presently being performed. As a result, according to such an excavator control device, performance of the entire system is substantially reduced. For that reason, the conventional control system has of the following drawbacks.
Firstly, delay in the response speed occurs and a control for the excavator is thus essentially unstable. Secondly, physical shock to the excavator is greatly increased because proper output power to a given input cannot be produced within a given time period. Therefore, the hydraulic discharging rate essential to the excavator in working may be unexpectedly changed. As a result, mechanical parts of the excavator are influenced by the increased physical shock. In FIG. 2, a portion 4 denotes the previously noted state. As seen from FIG. 2, in case of a single-task excavator system having a mechanism for the jobs generated, if the period of time between the generation and completion of the job is set 100 ms or less to produce a stable control of the entire system, a first job JOB1 is performed for the time duration 1 of approx. 30 ms and a second job JOB2 sequentially generated is performed for the time duration 2 of 60 ms. This job JOB2 is finished with the lapse of the period 2. Consequently, the first job JOB1 is restarted at a period 3. At this time, the previously set time of 100 ms has lapsed before the completion of the first job JOB1. Accordingly, an output signal produced at rest i.e., 10 ms of the set time cannot be employed as a control output or an unstable control output is produced.